The engineering, The weaknesses – Lingenfelter LTCC User Manual
Page 4
The Engineering
The OptiSpark itself is not a bad component; it is simply the result of poor planning and
execution. The OptiSpark is essentially a conventional distributor, however, it is much
more compact and does not have the facility for setting base timing. As accurate as it
may be, its condition can deteriorate rapidly, depending on climate and maintenance.
The OptiSpark is made up of two halves, the “Opti” half, which consists of a metal disc
with inner and outer rows of timing marks. The outer ring is for spark timing, the inner
is used in conjunction for fuel delivery.
Mitsubishi manufactures the optical pickup used in the OptiSpark. These pickups are
noted for their long-term durability.
The other half is the “Spark”. It is much like a conventional distributor, with a single
coil feeding 8 cylinders.
The Weaknesses
First, it is mounted below the water pump. If water is the OptiSpark’s enemy, then
antifreeze is its undoing.
Water, will, for the most part, simply evaporate, but not before causing carbon tracing
on the cap’s internal contacts. Over time, carbon tracing will cause serious problems for
the spark to jump from the rotor to the contact on the cap. Carbon tracing is easily
identified by the presence of a white crystalline substance on the points of the rotor
and/or cap.
Antifreeze is extremely bad! Antifreeze is an alcohol-based fluid, ethylene glycol, which
will eat the bearings inside the OptiSpark. The deterioration of the bearings will cause
the internal drive shaft to wobble, which results in the optical pickup not being able to
read the disc correctly, therefore, cause a timing/fuel delivery problem.
If you are experiencing a wandering idle, or a high RPM miss/stumble, you have a bad
case of carbon tracing.
Editor’s Note: I installed this kit on my 1992 Corvette, approximately 18 months after
my car was thoroughly drenched in a rainstorm of near epic proportions. The storm
drowned my car’s OptiSpark. Immediately after, it ran poorly due to the flooding of the
external cap towers and the wires. Time & WD-40 healed that, but time also caused
severe carbon tracing inside my OptiSpark’s cap and rotor. It was to a point that the car
would not hold idle.
Recommended Reading
For more detailed information on this subject, I suggest “Corvette Fuel Injection &
Electronic Ignition: 1982-2001”, by Charles O. Probst. This book is available from
Robert Bentley Publishers. Plus, a Helms Service Manual for the car you are servicing.
These are approximately $120.00 and are available directly from the publisher at
Do not bother with the Chilton’s or Haynes manuals; they are not specific enough for
this project.